Fluorinated intermediates are employed in the synthesis of a variety of chemical compounds, such as partially fluorinated polymers. Novel fluorinated intermediates and polymers derived therefrom are of significant interest to the chemical industry.
Partially fluorinated condensation polymers are known in the literature, see. e.g., I. L. Knunyants, C. Li, and V. V. Shokina, Russ. Chem. Rev., 32:461 (1963), and the references described therein. These polymers generally have been made to obtain materials with improved thermo-oxidative stability and solvent resistance, as compared to nonfluorinated polymers.
Many partially fluorinated condensation polymers have been made with perfluoro diacids, HOOC--(CF.sub.2).sub.n --COOH, as one component of the polymer, see, e.g., B. S. Marks & G. C. Schweiker, J. Polymer Sci. 43:229 (1960) wherein the synthesis of partially fluorinated polyamides containing perfluoro diacid units is disclosed. The polymers made from such perfluoro diacids, however, suffer from problems associated with the extreme hydrolytic instability of the perfluoroacyl functional groups. The strongly electron-withdrawing perfluoroalkyl group situated next to the carbonyl of the perfluoroacyl group activates the carbonyl to hydrolysis. It has been found that many of the resulting polymers hydrolyze in moist air.
P. Johncock, S. P. Barnett, & P. A. Rickard, J. Polymer Sci./Polymer Chem. 24:2033 (1986) disclose the synthesis of a diacid wherein the fluoroalkyl chain is separated from the acyl group by a methylene spacer, HOOC--CH.sub.2 --(CF.sub.2).sub.3 --CH.sub.2 --COOH. Although polyesters made with this diacid are more hydrolytically stable than those made from perfluoro diacids, these compositions still hydrolyze under mild conditions. This acid also suffers from the ready loss of two moles of hydrogen fluoride from the molecule.
P. L. Coe., N. E. Milner & J. A. Smith, J. Chem. Soc./Perkin I 654 (1975) disclose use of perfluoroalkylcopper compounds to form certain polyfluoroalkyl-substituted acids and alcohols. These compounds are said to be of practical interest as surfactants. In one reaction, (1E,6E)-3,3,4,4,5,5-hexafluoro-1,7-di-iodohepta-1,6-diene was reacted with copper(I) cyanide. Hydrolysis of the resulting unsaturated dinitrile yielded a diacid that was hydrogenated to give HOOC--CH.sub.2 CH.sub.2 --(CF.sub.2).sub.3 --CH.sub.2 CH.sub.2 --COOH.
U.S. Pat. No. 3,496,215 discloses hydrocyanation of unsaturated compounds using as a catalyst a compound of the structure Ni(PXYZ).sub.4 wherein X is OR; Y and Z are R or OR; and R is an alkyl or aryl radical of up to 18 carbon atoms. U.S. Pat. No. 3,496,217 discloses hydrocyanation of nonconjugated ethylenically unsaturated organic compounds using certain nickel complexes as a catalyst and certain zinc containing compounds as promoters. U.S. Pat. No. 3,496,218 discloses hydrocyanation of nonconjugated ethylenically unsaturated organic compounds using certain nickel complexes as catalysts and certain organoboron compounds as promoters.
C. A. Tolman et al., Adv. in Catalysis, 33:1 (1985) disclose homogeneous nickel-catalyzed olefin hydrocyanation, as well as unpromoted hydrocyanations of monoolefins and hydrocyanations promoted with Lewis acids.
The synthesis of compositions of the present invention starts with bis-2,2-trifluoromethyl-4,5-difluorodioxole, ##STR1## This dioxole was claimed by Resnick in U.S. Pat. No. 3,865,845.